1. Field of the Invention
The present invention relates to security apparatus in general and in particular to a key-actuated lock assembly having a linearly movable slot blocking member for selectively blocking the disk receiving slot in a disk drive.
2. Description of the Related Art
It is sometimes necessary to restrict access to a disk drive such as a floppy or CD read-only-memory (ROM) disk drive so as to prevent an unauthorized use thereof.
Heretofore, conventional floppy disk, CD ROM disk and cassette tape drive locks which have been used to prevent unauthorized use of a floppy disk, CD ROM disk or cassette tape drive have included apparatus which is inserted in the disk/cassette receiving slot in the drive as well as apparatus which is selectively placed in front of the entrance to the disk/cassette receiving slot in the drive so as to prevent a disk/cassette from being inserted into and/or removed from the slot in the drive.
Examples of floppy disk drive locks which comprise apparatus which is normally inserted in the slot of a floppy disk drive are the locks disclosed in U.S. Pat. Nos. 5,136,862; 5,117,661; 4,924,683; 4,907,111; 4,794,587; and 4,685,312.
Examples of cassette tape/CD ROM disk drive locks which comprise apparatus which is normally inserted in the slot of a cassette tape/CD ROM disk drive are the locks disclosed in U.S. Pat. Nos. 5,124,871; 5,022,242; 4,977,762; 4,959,979; 4,922,734; 4,856,304; 4,741,185; 4,655,057; 4,640,106; 4,616,490; and 4,527,405.
Among the disadvantages of the disk/cassette tape drive lock apparatus disclosed in the above-identified patents is that it tends to be bulky, must be manually removed from the apparatus and usually must be stored in a separate place when not being used to lock the apparatus, thus making the lock apparatus troublesome to use.
Another disadvantage of the lock apparatus which comprises a member which is inserted in the disk drive slot is that the lock apparatus requires that the disk slot be empty and therefore cannot be used to lock a disk in the slot.
Still another disadvantage is that the insertion of any object in a disk receiving slot of a drive gives rise to the possibility of inadvertently damaging the drive.
Examples of floppy disk drive locks which comprise apparatus which is selectively placed in front of the entrance of the slot in the disk drive so as to prevent a disk from being inserted into or removed from the disk receiving slot in the disk drive are the lock assemblies disclosed in U.S. Pat. Nos. 4,918,952 and 4,964,285. Each of the lock assemblies disclosed in these patents is distinguished by the manner in and means by which the disk receiving slot is blocked and is found to have one or more significant disadvantages. Among the disadvantages of the lock assembly disclosed in U.S. Pat. No. 4,918,952 ('952) are the following: the lock assembly requires a customized disk drive bezel which must be used in lieu of or as a replacement for a conventional bezel; it is expensive to manufacture; and it is time consuming to retrofit.
Another disadvantage of the lock assembly of '952 is that the locking bar used therein comprises a relatively small triangularly shaped member which is located on the backside of the bezel and therefore is difficult to see when in its blocking position, particularly if the drive is not directly in front of the operator.
Among the disadvantages of the lock assembly disclosed in U.S. Pat. No. 4,964,285 ('285) is that the blocking member requires a clearance on the face of the disk drive which is coextensive with the surface swept by the blocking member as it is rotated between its blocking and unblocking positions.
Another disadvantage of the lock assembly of '285 is that the size of the typical commercial embodiment of the lock assembly and its operation prevents its being used in connection with modern smaller sized half-height disk drives.
Another disadvantage of the lock assembly of '285 is that the blocking member comprises a relatively small triangularly-shaped member which, due to its size and configuration, does not present a particularly strong visual indication that access to the disk drive slot is being blocked even though its surface may comprise a bright color, e.g. red or the like.
Still another and very significant disadvantage of the lock assembly of '285 is that the blocking member cannot be moved by means of the rotation of a key inserted therein, as would normally be expected, but must be rotated manually in a separate operation after a proper key has been inserted in the lock assembly. Experience has shown that the proper operation of the lock assembly of '285 requires special instruction in that the need for separately rotating the blocking member after the insertion of a proper key in the lock assembly is not at all obvious to most people and that most people try to rotate the key and failing to do that assume that the wrong key is being used or that the lock is defective.